Cell type power supply device, circuit and electronic equipment

ABSTRACT

A cell type power supply device includes: a housing having a shape and dimensions based on a cell standard; a cell holder including an inner positive terminal and an inner negative terminal that are brought into contact with front and rear terminals of the external cell held in the housing; an outer positive terminal connected to the inner positive terminal; an outer negative terminal connected to the inner negative terminal; an output transistor interposed between the inner negative terminal and the outer negative terminal or between the inner positive terminal and the outer positive terminal; a control circuit that generates a control signal of the output transistor in accordance with a signal received via an antenna; and a detection resister interposed between the inner negative terminal and the outer negative terminal or between the inner positive terminal and the outer positive terminal in parallel with the output transistor to change a voltage of the outer negative terminal or the outer positive terminal with respect to a reference voltage in accordance with ON/OFF of a power switch.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is continuation application of International PatentApplication No. PCT/JP2016/077477 filed on Sep. 16, 2016, which is basedupon and claims the benefit of priority from the prior Japanese PatentApplication No. 2015-184076, filed Sep. 17, 2015, the entire contents ofwhich are incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to A cell type power supply device,circuit and electronic equipment.

BACKGROUND

There is a wireless system that enables wireless control of electrictoys by being switched on. In such a system, power is supplied to areceiver drive circuit by attaching a cell in a wireless communicationdrive device or by turning on a power supply switch of the device mainbody after attaching the cell. After that, the electrifying condition ismaintained and a current continues flowing unless the wirelesscommunication drive device is taken out from a cell box and the cell isremoved, or the power supply switch of the device main body is turnedoff.

Patent Literature 1 discloses a configuration in which an electric toyvehicle 100 holds in its cell holder a cell 50 and a box type wirelessreceiver drive storing a wireless receiver drive receiving substrateportion 20 including an antenna, a receiver IC, a tuning circuit, anamplifier circuit, an IC-controlled micro computer, and an IC motordriver, and an output terminal of the wireless receiver drive receivingsubstrate portion 20 is connected to an input terminal of a motor 107.

However, the literature does not include any technical descriptionrelating to power supply control of the wireless receiver drive, andleaves a problem that power supply cannot be stopped unless a powersupply switch is provided in the device main body and a user operatesthis switch, and an external cell that is built in the wireless receiverdrive is drained when the electric toy is not in use. To prevent thedrain of the external cell when the electric toy is not in use, it isnecessary to open the cell box of the electric toy, take out thewireless receiver drive, and further remove the external cell from thewireless receiver drive every time. Such a movable electric toy oftenemploys a screw fixing lid for the cell box in consideration of safety,which causes more inconvenience. If the electric toy is left uncared,the cell will be dead when the electric toy is used for playing nexttime; therefore, a new cell needs to be prepared and replaced with. Suchinconvenience has been obvious.

CITATION LIST Patent Literature

[Patent Literature 1] Japanese Utility Model No. 3143765

SUMMARY OF INVENTION Technical Problem

An object is to provide A cell type power supply device, circuit andelectronic equipment that reduce the consumption speed of an externalcell.

Solution to Problem

A cell type power supply device according to one embodiment of thepresent invention is attachable alone or in series with an other cell ina cell box of an external load device including a load, the cell box,and a power switch interposed between the load and the cell box. Thecell type power supply device comprises: a housing having a shape anddimensions based on a cell standard; a cell holder that holds anexternal cell in the housing, and includes an inner positive terminaland an inner negative terminal that are brought into contact with frontand rear terminals of the held external cell; an outer positive terminalprovided on a front end surface of the housing and connected to theinner positive terminal; an outer negative terminal provided on a rearend surface of the housing and connected to the inner negative terminal;an output transistor interposed between the inner negative terminal andthe outer negative terminal or between the inner positive terminal andthe outer positive terminal; a control circuit that generates a controlsignal of the output transistor in accordance with an RF signal receivedfrom an external information device via an antenna; and a detectionresister interposed between the inner negative terminal and the outernegative terminal or between the inner positive terminal and the outerpositive terminal in parallel with the output transistor to change avoltage of the outer negative terminal or the outer positive terminalwith respect to a reference voltage in accordance with ON/OFF of thepower switch.

An electronic equipment according to one embodiment of the presentinvention comprises: a load; a power supply box that holds a powersupply; a power switch interposed between the load and the power supplybox; a power switch detection unit that detects ON/OFF of the powerswitch; a circuit cutoff/conduction unit that cuts or allows electricalconnection between the load and the power supply box in accordance witha control signal; and a control unit that generates the control signalin accordance with an RF signal received from an external informationdevice via an antenna, wherein the control unit switches between ON andOFF of a transmitting/receiving operation of the RF signal via theantenna in accordance with ON/OFF of the power switch which is detectedby the power switch detection unit.

A circuit according to one embodiment of the present invention isconfigured with an external load, a power supply, and a power switch.The circuit comprises: a power switch detection unit that detects ON/OFFof the power switch; a circuit cutoff/conduction unit that cuts orallows electrical connection between the external load and the powersupply in accordance with a control signal; and a control unit thatgenerates the control signal in accordance with an RF signal receivedfrom an external information device via an antenna, wherein the controlunit switches between ON and OFF of a transmitting/receiving operationof the RF signal via the antenna in accordance with ON/OFF of the powerswitch which is detected by the power switch detection unit.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view showing an exterior of A cell type powersupply device according to a first embodiment.

FIG. 2 is a diagram showing an internal structure of the cell type powersupply device according to the first embodiment.

FIG. 3 is a diagram showing a mode of use of the cell type power supplydevice according to the first embodiment.

FIG. 4 is an equivalent circuit diagram showing an example of the celltype power supply device according to the first embodiment.

FIG. 5 is an equivalent circuit diagram showing another example of thecell type power supply device according to the first embodiment.

FIG. 6 is a flowchart showing a procedure of a process for changing acommunication interval by the cell type power supply device of FIG. 5.

FIG. 7 is an equivalent circuit diagram showing an example of A celltype power supply device according to a second embodiment.

FIG. 8 is a timing chart showing changes of the input signal of an ENterminal of a DC-DC converter with respect to output of the RFIC of FIG.7.

FIG. 9 is an equivalent circuit diagram showing an example of A celltype power supply device according to a third embodiment.

FIG. 10 is an equivalent circuit diagram showing an example of A celltype power supply device according to a fourth embodiment.

FIG. 11 is a timing chart showing changes of the input/output of eachterminal under PWM control by the RF IC of FIG. 10.

FIG. 12 is a flowchart showing a procedure of a process for switchingon/off the transmitting/receiving operation by a control unit of the RFIC of FIG. 10.

FIG. 13 is an equivalent circuit diagram showing an example of A celltype power supply device according to a fifth embodiment.

FIG. 14 is a diagram showing a terminal voltage level of each transistorwhich changes in accordance with ON/OFF of the power switch of FIG. 13.

DESCRIPTION OF PREFERRED EMBODIMENTS

Hereinafter, A cell type power supply device 100 comprising a wirelessfunction according to one embodiment of the present invention will bedescribed with reference to the drawings. In the following description,structural elements having approximately the same function andconfiguration will be assigned with the same reference numeral, andredundant descriptions will be given only where necessary.

An object of the present embodiment is to provide A cell type powersupply device, circuit and electronic equipment that can control ON/OFFof the cell type power supply device in accordance with a switch (suchas a power switch) connected to the cell type power supply device evenwhen the cell type power supply device is kept attached in the cell box.In addition, one of the objects is to provide a cell type power supplydevice, circuit and electronic equipment that can control ON/OFF of atransmitting/receiving operation of the cell type power supply devicerather than turning on/off the cell type power supply device inaccordance with an external power switch. One of the objects is toprovide A cell type power supply device, circuit and electronicequipment that can detect ON or OFF of a switch (such as a power switch)in an electronic equipment and adjust the output to a load (such as awireless communication device or a power source). Furthermore, one ofthe objects is to provide a circuit, electronic equipment and powersupply method that can prevent a CPU breakdown etc. caused by acounterelectromotive voltage that occurs due to voltage levelstabilization, a level shift, logical consistency, or a load.

FIG. 1 is a perspective view showing an exterior of the cell type powersupply device 100 having a wireless communication function according toa first embodiment. FIG. 2 is a diagram showing an internal structure ofthe cell type power supply device 100 according to the first embodiment.The cell type power supply device 100 having a wireless communicationfunction according to the first embodiment (hereinafter, simply referredto as A cell type power supply device 100) has a shape and externaldimensions based on a cell standard. Typically, the cell type powersupply device 100 is made by a columnar body having a height anddiameter based on the AA standard (the single cell). However, the celltype power supply device 100 may have a shape and dimensions based onanother cell standard. Here, descriptions are provided on the assumptionthat the cell type power supply device 100 is based on the AA standard.The cell type power supply devices 100 according to the second to fifthembodiments also has the same shape and dimensions as those of the firstembodiment.

A main body 117 of the cell type power supply device 100 is wrapped by acolumnar housing 118 having the same shape and dimensions as those ofthe AA size cell standard. A circle conductive plate is attached as anouter positive terminal 103 at the center of a top surface (alsoreferred to as a front end surface) of the main body 117. The terminalis also referred to as an electrode. A circle conductive plate isattached as an outer negative terminal 104 at the center of a bottomsurface (also referred to as a rear end surface) of the main body. Aportion of the peripheral surface of the housing 118 is cut in an ovalshape. The length of the cut portion 119 is equal to that of AAA cells,and the width is a little larger than that of AAA cells. A user caninsert an AAA cell into or remove it from a cell holder 102 through thecut portion 119. The shape of the cell holder 102 is a columnar spacehaving a length and diameter based on the AAA standard. The central axisof the cell holder 102 is offset in a radial direction with respect tothe columnar central axis of the cell type power supply device 100. Thisoffset provides a small space between the housing 118 and the cellholder 102. In this small space, a substrate 107 that realizes variousfunctions of the cell type power supply device 100 is mounted.

A conductive plate is attached as an inner positive terminal 105 at thecenter of the front end of the cell holder 102, i.e., on the same sideas the outer positive terminal 103. A conductive plate having springproperty is attached as an inner negative terminal 106 at the center ofthe rear end of the cell holder 102, i.e., on the same side as the outernegative terminal 104. The positive terminal of the AAA cell held in thecell holder 102 is brought into contact with the inner positive terminal105, and the negative terminal of the AAA cell is brought into contactwith the inner negative terminal 106. The inner negative terminal 106 isconnected to the outer negative terminal 104 and the substrate 107 via adistribution cable 108. The inner negative terminal 106 and the outernegative terminal 104 may be a common conductive plate. The innerpositive terminal 105 is connected to the substrate 107 via adistribution cable 109. The outer positive terminal 103 is connected tothe substrate 107 via a distribution cable 110.

FIG. 3 is a diagram showing a mode of use of the cell type power supplydevice 100 of FIG. 1. As shown in FIG. 3, an external load device 111includes a load 115, a cell box 112, and a power switch (externalswitch) 114. Here, the external load device 111 is driven by one AAcell. The cell type power supply device 100 is attached alone in thecell box 112. The external load device 111 is an electronic equipmentsuch as an electric toy, an electric tools toy, a disaster preventionsensor, a security sensor, a flashlight, a bicycle light, a cell-poweredcooker, an electrical float, an electric pet feeding device, acell-powered fan, or a cell-powered hand soap dispenser. Here, theexternal load device 111 is described as an electric toy driven by amotor 115. The electric toy is, for example, a miniature train orminiature car that moves at a fixed speed when being switched on. Awheel 116 is connected to the motor 115 via a transmission mechanism.When the power switch 114 is turned on, an electrical connection betweenthe motor 115 and the cell box 112 is secured. When the power switch 114is turned off, the motor 115 is electrically cut from the cell box 112.An external information device 200 is typically a mobile digitalelectronic equipment, such as a smartphone, a portable telephone, atablet terminal, or a radio control communication device, which has acommunication function and an operation function etc. Of course, theexternal information device 200 may be a dedicated device for operatingthe cell type power supply device 100. A user can turn on/off the motor115 by operating the external information device 200. In addition, auser can designate any value between 0% (no drive signal output) and100% (maximum drive signal output) as a motor output instruction valueby operating the external information device 200. The cell type powersupply device 100 is wirelessly connected to the external informationdevice 200. A motor output instruction selected by a user is wirelesslytransmitted from the external information device 200 to the cell typepower supply device 100. As will be described later, an outputtransistor 120 is interposed between the outer negative terminal 104 andthe inner negative terminal 106 or between the outer positive terminal103 and the inner positive terminal 105 of the cell holder 102 of thecell type power supply device 100. The cell type power supply device 100adjusts a power output by turning on/off the output transistor 120 inaccordance with the motor output instruction from the externalinformation device 200.

First Embodiment

The cell type power supply device 100 according to the first embodimentis turned on/off in accordance with ON/OFF of the power switch 114.Specifically, the wireless communication function of the cell type powersupply device 100 is turned on/off in accordance with ON/OFF of thepower switch 114. FIG. 4 is an equivalent circuit diagram showing anexample of the cell type power supply device 100 according to the firstembodiment. Here, the cell type power supply device 100 is attachedalone in the cell box 112. An external cell is attached in the cellholder 102 of the cell type power supply device 100.

(Circuit Configuration)

The cell type power supply device 100 according to the first embodimentincludes an output transistor 120, a DC-DC converter (internal powersupply circuit) 121, an RF IC (control circuit) 122, an inverter 123,pull-up resister (detection resister) 124, and pull-up resistor 125.Those electronic components are mounted on the substrate 107.

The output transistor 120 is typically a P-channel MOSFET, and isinterposed between the inner positive terminal 105 and the outerpositive terminal 103. The source terminal of the output transistor 120is connected to the inner positive terminal 105 via distribution cable109. The drain terminal of the output transistor 120 is connected to theouter positive terminal 103 via distribution cable 110.

Pull-up resister (detection resister) 124 is arranged between the innerpositive terminal 105 and the outer positive terminal 103 in parallelwith the output transistor 120. Pull-up resister 125 is interposedbetween the gate terminal of the output transistor 120 and the innerpositive terminal 105.

The Vcc terminal of the DC-DC converter 121 is connected to the innerpositive terminal 105, the EN terminal thereof is connected to the outerpositive terminal 103, and the OUTPUT terminal thereof is connected tothe Vdd terminal of the RF IC 122. The DC-DC converter 121 is aninternal power supply circuit, and raises the cell voltage Vcc of theAAA cell attached in the cell holder 102 to the power supply voltage Vddof, for example, 3.0V for internal circuit operation. The DC-DCconverter 121 is configured to supply the power supply voltage Vdd tothe RF IC 122 when its EN terminal is at the high level, and not tosupply the power supply voltage Vdd to the RF IC 122 when its ENterminal is at the low level. Here, the DC-DC converter 121 functions asan internal power supply circuit for supplying a drive voltage of the RFIC 122; however, the internal power supply circuit for supplying a drivevoltage to the RF IC 122 may be an electronic component etc. other thanthe DC-DC converter 121.

The inverter 123 is interposed between the drain terminal of the outputtransistor 120 and the EN terminal of the DC-DC converter 121. Arrangingthe inverter 123 in the input stage of the DC-DC converter 121 can avoida breakdown etc. of the DC-DC converter caused by an inverse voltagegenerated in the motor 115. The input terminal of the inverter 123 isconnected to the drain terminal of the output transistor 120, and theoutput terminal thereof is connected to the EN terminal of the DC-DCconverter 121. The inverter 123 inverts input signals and then outputsthe inverted signals.

The RF IC 122 is a control circuit that is driven by a power supplyvoltage Vdd and performs centralized control of the cell type powersupply device 100. An antenna 127 for wireless communication isconnected to the ANT terminal of the RF IC 122. The OUTPUT terminal ofthe RF IC 122 is connected to the gate terminal of the output transistor120. The RF IC 122 functionally includes a communication unit, a controlsignal generation unit, and a control unit, etc. The communication unitis driven in accordance with control of the control unit, and performs awireless communication based on the Bluetooth (registered trademark)standard with the external information device 200 via the antenna 127.The RF IC 122 may perform a wireless communication based on anotherwireless communication standard, such as a wireless LAN standard. Thecommunication unit receives a code wireless signal that indicates ON/OFFof the motor 115 from the external information device 200 via theantenna 127. When a code wireless signal indicating ON of the motor 115is received, the control signal generation unit is driven in accordancewith control of the control unit, and generates a low-level gate controlsignal. When a code wireless signal indicating OFF of the motor 115 isreceived, the control signal generation unit generates a high-level gatecontrol signal in accordance with control of the control unit.Alternatively, the control signal generation unit is turned off inaccordance with control of the control unit, thereby releasing theOUTPUT terminal. The “high-level” of the gate control signal generatedby the control signal generation unit refers to a voltage valuesufficiently lower than the threshold voltage Vth of the outputtransistor 120, and the “low-level” refers to a voltage valuesufficiently higher than the threshold voltage Vth of the outputtransistor 120.

The ON/OFF of the output transistor 120 is controlled by the voltage(gate voltage) applied by the gate control signal input to the gate.When the gate voltage is at a low level sufficiently lower than thethreshold voltage Vth, a channel is formed between the source and drain,and the maximum drain current flows. In this state, the outputtransistor 120 is ON. When the output transistor 120 is turned on, acurrent flows between the outer positive terminal 103 and outer negativeterminal 104 of the cell type power supply device 100 via the built-inbuttery. When the power switch 114 of the external load device 111 isON, a current flows between the outer positive terminal 103 and theouter negative terminal 104 of the cell type power supply device 100,and the motor 115 of the external load device 111 is driven. Incontrast, when the gate voltage is at a high level sufficiently higherthan the threshold voltage Vth, a drain current does not flow betweenthe source and drain. In this state, the output transistor 120 is OFF.When the output transistor 120 is turned off, the outer positiveterminal 103 and the outer negative terminal 104 of the cell type powersupply device 100 are cut from each other. Accordingly, even when thepower switch 114 of the external load device 111 is ON, the circuit ofthe external load device 111 is cut off, and the motor 115 is notdriven.

(Operation Description)

Hereinafter, the state in which the power switch 114 is OFF is called anOFF state of the external load device 111, the state in which the powerswitch 114 is ON, but the motor 115 is not operating is called a standbystate of the external load device 111, and the state in which the motor115 is operating is called an operating state of the external loaddevice 111. In addition, the state in which the control unit of the RFIC 122 is not driven is called an OFF state of the cell type powersupply device 100, the state in which the transmitting/receivingoperation by the wireless communication unit is OFF is called a standbystate of the cell type power supply device 100, the state in which thetransmitting/receiving operation by the wireless communication unit isON is called a communication possible state of the cell type powersupply device 100, and the state in which a gate control signal isoutput by the RF IC 122 is called an operating state of the cell typepower supply device 100.

A feature of the cell type power supply device 100 according to thefirst embodiment lies in arranging pull-up resister (detection resister)124 between the inner positive terminal 105 and the outer positiveterminal 103 in parallel with the output transistor 120 so that thevoltage level of the outer positive terminal 103 changes with respect tothe reference potential in accordance with ON/OFF of the power switch114. Here, let us assume the reference potential is the GND potential.When the power switch 114 is OFF, the outer positive terminal 103 isconnected to the inner positive terminal 105 via pull-up resister 124,and thus is at the high level. In contrast, when the power switch 114 isswitched from OFF to ON, the outer positive terminal 103 is connected tothe GND via the power switch 114, and thus is switched from the highlevel to the low level. In this way, the voltage level of the outerpositive terminal 103 changes in accordance with ON/OFF of the powerswitch 114. The cell type power supply device 100 detects ON/OFF of thepower switch 114 by detecting a change in the voltage level of the outerpositive terminal 103.

When the external load device 111 is in the initial state, the inputterminal of the inverter 123 is connected to the inner positive terminal105 via pull-up resister 124, and thus is at the high level, and the ENterminal of the DC-DC converter 121 (output terminal of the inverter123) is at the low level. Accordingly, the power supply voltage Vddgenerated by the DC-DC converter 121 is not supplied to the RF IC 122.Therefore, the cell type power supply device 100 is in the OFF state.

When the power switch 114 is turned on, the input terminal of theinverter 123 is connected to the GND via the power switch 114, and thusis switched from the high level to the low level, and the EN terminal ofthe DC-DC converter 121 is switched from the low level to the highlevel. Accordingly, the power supply voltage Vdd generated by the DC-DCconverter 121 is supplied to the RF IC 122, thereby driving the controlunit of the RF IC 122, whereby the state of the cell type power supplydevice 100 transitions from the OFF state to the standby state. Inresponse to the driving of the RF IC 122, the transmitting/receivingoperation by the wireless communication unit is switched from OFF to ONin accordance with control of the control unit, whereby the cell typepower supply device 100 transitions from the standby state to thecommunication possible state.

When the power switch 114 is turned off, the input terminal of theinverter 123 is again connected to the inner positive terminal 105 viapull-up resister 124, and thus is switched from the low level to thehigh level, thereby turning off the RF IC 122 and switching the state ofthe cell type power supply device 100 from the communication possiblestate to the OFF state.

When the cell type power supply device 100 is in the communicationpossible state, the cell type power supply device 100 can performvarious processes in accordance with wireless signals received from theexternal information device 200. For example, when a code wirelesssignal indicating ON of the motor 115 is received from the externalinformation device 200 via the wireless communication unit, the controlsignal generation unit generates a low-level gate control signal. Thegate terminal of the output transistor 120 is thereby brought into thelow level; therefore, the output transistor 120 is turned on, and themotor 115 is driven. In this way, a user can turn on the external loaddevice 111 at any time by operating the external information device 200.

As described in relation to FIG. 4, the cell type power supply device100 according to the first embodiment can switch the state of the celltype power supply device 100 from the OFF state to the communicationpossible state in response to turning on of the power switch 114 of theexternal load device 111, and from the communication possible state tothe OFF state in response to turning off of the power switch 114.Therefore, the cell type power supply device 100 does not need to have aswitch for switching between the OFF state and the communicationpossible state, which contributes to miniaturization and parts costreduction of the device. In addition, when the external load device 111is in the initial state, the DC-DC converter 121 and RF IC 122 are notdriven, which can reduce unnecessary power consumption.

The cell type power supply device 100 according to the first embodimenthas a configuration in which the output signal of the inverter 123 isinput to the DC-DC converter 121; however, it may have a configurationin which the output signal of the inverter 123 is input to the RF IC122.

FIG. 5 is an equivalent circuit diagram showing another example of thecell type power supply device 100 according to the first embodiment. Theoutput terminal of the inverter 123 is connected to the INPUT terminalof the RF IC 122. Arranging the inverter 123 in the input stage of theRF IC 122 can avoid a breakdown etc. of the RF IC 122 caused by aninverse voltage generated in the motor 115. The EN terminal of the DC-DCconverter 121 is connected to the inner positive terminal 105.Therefore, while the external cell is attached in the cell holder 102,the DC-DC converter 121 is ON, and the cell type power supply device 100is in the standby state.

The RF IC 122 switches between ON and OFF of the RF signaltransmitting/receiving operation via the antenna 127 in accordance withON/OFF of the power switch 114 which is determined based on the voltagelevel of the outer positive terminal 103. As described in relation toFIG. 4, the ON/OFF of the power switch 114 can be determined based onthe voltage level of the output signal of the inverter 123. When thepower switch 114 is ON, the output signal of the inverter 123 is at thehigh level, and when the power switch 114 is OFF, the output signal ofthe inverter 123 is at the low level. Accordingly, when the INPUTterminal is at the low level, the power switch 114 is determined asbeing OFF; therefore, the transmitting/receiving operation by thewireless communication unit is turned off in accordance with control ofthe control unit, and the state of the cell type power supply device 100is switched from the communication possible state to the standby state.When the INPUT terminal is at the high level, the power switch 114 isdetermined as being ON; therefore, the transmitting/receiving operationby the wireless communication unit is turned on in accordance withcontrol of the control unit, and the state of the cell type power supplydevice 100 is switched from the standby state to the communicationpossible state. The switching between ON and OFF of thetransmitting/receiving operation of the wireless communication unit bythe control unit is performed by controlling the supply of the drivevoltage Vdd to a communication module of the wireless communicationunit. Of course, the switching between ON and OFF of thetransmitting/receiving operation of the wireless communication unit bythe control unit may be performed by controlling output of a radio waveby software in a state where the communication module is driven.

As described in relation to FIG. 5, according to another example of thecell type power supply device 100 according to the first embodiment, thestate of the cell type power supply device 100 can be switched from thestandby state to the communication possible state in response to turningon of the power switch 114 of the external load device 111, and can beswitched from the communication possible state to the standby state inresponse to turning off of the power switch 114. Therefore, the celltype power supply device 100 does not need to have a switch forswitching between the standby state and the communication possiblestate, which contributes to miniaturization and parts cost reduction ofthe device. In addition, when the external load device 111 is in theinitial state, the DC-DC converter 121 and RF IC 122 are not driven,which can reduce unnecessary power consumption.

Furthermore, with the circuit configuration as shown in FIG. 5, the celltype power supply device 100 is in the standby state while the externalcell is attached in the cell holder 102. The control unit may perform,in accordance with ON/OFF of the power switch 114, a process other thanturning on/off of the transmitting/receiving operation by the wirelesscommunication unit. For example, the control unit changes thecommunication interval between communications with the externalinformation device 200 in accordance with ON/OFF of the power switch114. FIG. 6 is a flowchart showing a procedure of a process for changinga communication interval by the cell type power supply device of FIG. 5.When the external load device 111 is in the initial state, the cell typepower supply device 100 is in the standby state. The wirelesscommunication unit communicates with the external information device 200at communication intervals T1 in accordance with control of the controlunit (step S11). When the power switch 114 is turned on (step S12),i.e., when the INPUT terminal of the RF IC 122 is switched from the lowlevel to the high level, the wireless communication unit communicateswith the external information device 200 at communication intervals T2shorter than communication intervals T1 in accordance with control ofthe control unit (step S13). Communication intervals T1 and T2 may bepreset, or may be values set by a user via the external informationdevice 200. When the power switch 114 is turned off (step S14), i.e.,the INPUT terminal of the RF IC 122 is switched from the high level tothe low level, the processing returns to step S11, and the wirelesscommunication unit communicates with the external information device 200at communication intervals T1 in accordance with control of the controlunit.

When the external load device 111 is in the standby state, shorteningthe interval between communications with the external information device200 can improve the response speed of the cell type power supply device100 to an instruction from the external information device 200, and canimprove connectivity of the communication with the external informationdevice 200. In addition, when the external load device 111 is in the OFFstate (power switch 114 is OFF), prolonging the interval betweencommunications with the external information device 200 can reduceunnecessary power consumption.

Second Embodiment

The cell type power supply device 100 according to the second embodimentcan use a PWM signal as the gate control signal of the output transistor120 of the cell type power supply device 100 according to the firstembodiment.

(Circuit Configuration)

FIG. 7 is an equivalent circuit diagram showing an example of the celltype power supply device 100 according to the second embodiment. Onefeature of the cell type power supply device 100 according to the secondembodiment lies in arranging an OR circuit 131 in the preceding stage ofthe EN terminal of the DC-DC converter 121.

The OR circuit 131 has two input terminals and one output terminal. Whenat least one of the two input terminals is at the high level, the ORcircuit 131 outputs a high-level signal. When both of the two outputterminals are at the low level, the OR circuit 131 outputs a low-levelsignal. The output terminal of the OR terminal 131 is connected to theEN terminal of the DC-DC converter 121. A low-pass filter 132 isinterposed between the output terminal of the OR circuit 131 and the ENterminal of the DC-DC converter 121. The low-pass filter 132 includes,for example, a resister and a capacitor. The low-pass filter 132 allowscomponents of frequencies lower then a cutoff frequency, downconvertscomponents of frequencies higher than the cutoff frequency, and controlsinstantaneous signal fluctuations caused by noise etc.

One input terminal (first input terminal) of the OR circuit 131 isconnected to the OUTPUT terminal of the RF IC 122. The other inputterminal (second input terminal) of the OR circuit 131 is connected tothe inner positive terminal 105 via a detection transistor 130. Thefirst and second input terminals of the OR circuit 131 are connected tothe GND via pull-down resisters 136 and 135.

An inverter 133 is interposed between the OUTPUT terminal of the RF IC122 and the gate terminal of the output transistor 120. The output ofthe inverter 133 is input to the gate of the output transistor 120.

The detection transistor 130 is typically a P-channel MOSFET and detectsON/OFF of the power switch 114. The drain terminal of the detectiontransistor 130 is connected to the second input terminal of the ORcircuit 131, the source terminal thereof is connected to the innerpositive terminal 105, and the gate terminal thereof is connected to theouter positive terminal 103. As in the first embodiment, the pull-upresister (detection resister) 134 is provided between the inner positiveterminal 105 and the outer positive terminal 103 in parallel with theoutput transistor 120. Therefore, the signal level of the outer positiveterminal 103 can be switched between the low level and the high level inaccordance with ON/OFF of the power switch 114. By connecting the gateterminal of the detection transistor 130 to the outer positive terminal103, the detection transistor 130 can be turned on/off in accordancewith ON/OFF of the power switch 114.

The control signal generation unit generates a gate control signalcorresponding to a received motor output instruction value in accordancewith control of the control unit. Here, a PWM (pulse width signalmodulation) signal is provided as the gate control signal. For example,when the motor output instruction value is 0%, the control signalgeneration unit generates a 0% duty cycle (only low level) PWM signal.When the motor output instruction value is 100%, the control signalgeneration unit generates a 100% duty cycle (only high level) PWMsignal. When the motor output instruction value is 50%, the controlsignal generation unit generates a 50% duty cycle (1-to-1 lowlevel-to-high level ratio) PWM signal. The PWM signal generated by thecontrol signal generation unit is input to the input transistor 120 as agate control signal.

When the PWM signal is at the high level (the gate terminal is at thelow level), the output transistor 120 is ON. Therefore, the circuit ofthe external load device 111 is brought into conduction, and the motor115 is driven. When the PWM signal (gate control signal) is at the lowlevel (the gate terminal is at the high level), the output transistor120 is OFF. Therefore, the circuit of the external load device 111 iscut off, and the motor 115 is not driven. While the PWM signal is inputto the gate terminal, the motor 115 repeats starting rotation andstopping rotation in a predetermined cycle. When the output transistor120 is switched from ON to OFF, the motor 115 gradually slows down itsrotation because of its coil characteristics. In contrast, when theoutput transistor 120 is switched from OFF to ON, the rotation speeds upagain. By using those characteristics, the motor 115 can be rotated atgiven revs by PWM control.

(Operation Description)

One feature of the cell type power supply device 100 according to thesecond embodiment lies in arranging the OR circuit 131 in the precedingstage of the DC-DC converter 121. The OR circuit 131 receives a gatecontrol signal output from the RF IC 122 and a detection signal of thedetection transistor 130 as inputs, and outputs a high-level orlow-level signal to the DC-DC converter 121 as an OR operation result.Accordingly, when the power switch 114 is ON, the cell type power supplydevice 100 can be prevented from switching from the communicationpossible state to the OFF state or the standby state.

Specifically, when the external load device 111 is in the initial state,the detection transistor 130 and the RF IC 122 are both OFF; therefore,the first and second input terminals of the OR circuit 131 are connectedto the GND via the pull-down resisters 136 and 135, respectively, andthus are at the low level. Consequently, the power supply voltage Vddgenerated by the DC-DC converter 121 is not supplied to the RF IC 122.Hence, the cell type power supply device 100 is in the OFF state.

When the power switch 114 is turned on, the gate terminal of thedetection transistor 130 is connected to the GND via the power switch114, and thus is switched from the high level to the low level. Thesecond input terminal of the OR circuit 131 is connected to the innerpositive terminal 105 via the detection transistor 130, and is switchedfrom the low level to the high level, whereby the OR circuit 131 outputsa high-level signal. The EN terminal of the DC-DC converter 121 isswitched from the low level to the high level, and the power supplyvoltage Vdd generated by the DC-DC converter 121 is supplied to the RFIC 122, whereby the control unit of the RF IC 122 is driven, and thestate of the cell type power supply device 100 is switched from the OFFstate to the standby state. In response to the driving of the controlunit of the RF IC 122, the transmitting/receiving operation by thewireless communication unit is switched from OFF to ON in accordancewith control of the control unit, and the state of the cell type powersupply device 100 is switched from the standby state to thecommunication possible state. The power output of the output transistor120 is adjusted in accordance with a PWM signal corresponding to themotor output instruction from the external information device 200.

When the output transistor 120 is turned off (when the gate terminal ofthe output transistor 120 is at the high level) in the state where thepower switch 114 is ON, the gate terminal of the detection transistor130 is connected to the GND via the power switch 114, and thus is at thelow level, whereby the detection transistor 130 is turned on. By turningon the detection transistor 130, the second input terminal of the ORcircuit 131 is connected to the inner positive terminal 105 via thedetection transistor 130 and thus is at the high level, whereby the ORcircuit 131 outputs a high-level signal to the DC-DC converter 121.

When the output transistor 120 is turned on (when the gate terminal ofthe output transistor 120 is at the low level) in the state where thepower switch 114 is ON, the gate terminal of the detection transistor130 is connected to the inner positive terminal 105 via the outputtransistor 120, and thus is at the high level, whereby the detectiontransistor 130 is turned off. The first input terminal of the OR circuit131 is connected to the GND via pull-down resister 136, and thus is atthe low level. In contrast, when the output transistor 120 is ON, thegate control signal output from the OUTPUT terminal is at the highlevel. Therefore, the first input terminal of the OR circuit 131 isconnected to the OUTPUT terminal and thus is at the high level, wherebythe OR circuit 131 outputs a high-level signal to the DC-DC converter121.

Accordingly, while the output transistor 120 is turned off by the gatecontrol signal, the first input terminal of the OR circuit 131 is at thehigh level, and the second input terminal thereof is at the low level;therefore, the OR circuit 131 outputs a high-level signal. In contrast,while the output transistor 120 is ON, the first input terminal of theOR circuit 131 is at the low level, and the second input terminalthereof is at the high level; therefore the OR circuit 131 outputs ahigh-level signal.

In this way, as long as the power switch 114 is ON, even when the outputtransistor 120 is turned on/off by a gate control signal, the OR circuit131 can maintain its ON state. Hence, even when a PWM signal is used asthe gate control signal, the cell type power supply device 100 can bemaintained in the communication possible state. Enabling use of the PWMsignal makes it possible to provide a power supply device that canfreely adjust the power output in the 0%-to-100% range. Accordingly, forexample, only by attaching the cell type power supply device 100according to the second embodiment in the cell box 112, the externalload device 111 which does not originally have means for adjusting thepower output can be provided with the means for adjusting the poweroutput. A user can freely change the operation speed of, for example,the electric toy in which the cell type power supply device 100 isattached by operating the external information device 200.

In the second embodiment, the output signal of the OR circuit 131 isinput to the DC-DC converter 121. Alternatively, the output signal ofthe OR circuit 131 may be input to the INPUT terminal of the RF IC 122,and the transmitting/receiving operation by the wireless communicationunit may be switched on/off by the control unit in accordance with thesignal level of the INPUT terminal.

Third Embodiment

In the first and second embodiments, described is a circuit example ofthe case where a P-channel MOFET is used as the output transistor 120;however, an N-channel MOSFET may be used as the output transistor 120.Some N-channel MOSFETs are cheaper than P-channel MOSFETs, and use of anN-channel MOSFET can reduce the parts cost of the cell type power supplydevice 100. In addition, some N-channel MOSFETs have a higher withstandvoltage than P-channel MOSFETs, and use an N-channel MOSFET can increasethe number of external cells that can be connected to the cell typepower supply device 100 in series. It is expected that it expands therange of the external load device 111 for which the cell type powersupply device 100 can be used. The output transistor 120 may be abipolar transistor. In that case, a base control signal is substitutedfor a gate control signal.

(Circuit Configuration)

FIG. 9 is an equivalent circuit diagram showing an example of the celltype power supply device 100 according to the third embodiment. FIG. 9shows a circuit example of the case where the output transistor 120 ofthe circuit of FIG. 7 is changed from a P-channel MOSFET to an N-channelMOSFET. As shown in FIG. 9, the wiring between the OR circuit 131, theDC-DC converter 121, and the RF IC 122 is the same as that of thecircuit of FIG. 7. The output transistor 140 is interposed between theinner negative terminal 106 and the outer negative terminal 104. Thesource terminal of the output transistor 140 is connected to the innernegative terminal 106, the drain terminal thereof is connected to theouter negative terminal 104, and the gate terminal thereof is connectedto the OUTPUT terminal of the RF IC 122.

In the third embodiment, two detection transistors are used to detectON/OFF of the power switch 114. The first detection transistor 130 is aP-channel MOSFET. The source terminal of the first detection transistor130 is connected to the inner positive terminal 105, the gate terminalthereof is connected to the drain terminal of the second detectiontransistor 141, and the drain terminal thereof is connected to thesecond input terminal of the OR circuit 131. When the first detectiontransistor 130 is OFF, the second input terminal of the OR circuit 131is connected to the GND via pull-down resister 135 to stabilize thesecond input terminal of the OR circuit 131 at the low level. When thesecond detection transistor 141 is OFF, the gate terminal of the secondtransistor 130 is connected to the inner positive terminal 105 viapull-up resister 134 to stabilize the gate terminal of the firstdetection transistor 130 at the high level. The second detectiontransistor 141 is an N-channel MOSFET. The source terminal of the seconddetection transistor 141 is connected to the GND, the gate terminalthereof is connected to the outer negative terminal 104, and the drainterminal thereof is connected to the gate terminal of the firstdetection transistor 130. When the power switch 114 is OFF, the gateterminal of the second detection transistor 141 is connected to the GNDvia pull-down resister 143 to stabilize the gate terminal of the seconddetection transistor 141 at the low level.

(Operation Description)

When the external load device 111 is in the initial state (the powerswitch 114 is OFF), the second detection transistor 141 is OFF becauseits gate terminal is connected to the GND via pull-down resister 143 andthus is at the low level. The first detection transistor 130 is OFFbecause its gate terminal is connected to the inner positive terminal105 via pull-up resister 134 and thus is at the high level. Since theexternal load device 111 is in the initial state, and the RF IC 122 isnot driven, a gate control signal is not output. Therefore, the ORcircuit 131 outputs a low-level signal because its first and secondinput terminals are connected to the GND via pull-down resisters 136 and135, respectively, and thus are at the low level.

When the power switch 114 is turned on, the second detection transistor141 is turned on because its gate terminal is connected to the innerpositive terminal 105 via the outer negative terminal 104, the motor115, the power switch 114, and the outer positive terminal 103, and thusis at the high level. The first detection transistor 130 is turned onbecause its gate terminal is connected to the GND via the seconddetection transistor 141, and thus is at the low level. The second inputterminal of the OR circuit 131 is connected to the inner positiveterminal 105 via the first detection transistor 130, and is switchedfrom the low level to the high level, whereby the OR circuit 131 outputsa high-level signal. The EN terminal of the DC-DC converter 121 isswitched from the low level to the high level, and the power supplyvoltage Vdd generated by the DC-DC converter 121 is supplied to the RFIC 122, thereby driving the control unit of the RF IC 122, and switchingthe state of the cell type power supply device 100 from the OFF state tothe standby state. In response to the driving of the control unit of theRF IC 122, the transmitting/receiving operation by the wirelesscommunication unit is switched from OFF to ON in accordance with controlof the control unit, and the state of the cell type power supply device100 is switched from the standby state to the communication possiblestate. The power output of the output transistor 140 is adjusted inaccordance with the PWM signal corresponding to the motor outputinstruction from the external information device 200.

The cell type power supply device 100 according to the third embodimentas described above can switch its state between the OFF state and thecommunication possible state in accordance with ON/OFF of the powerswitch 114. In addition, as long as the power switch 114 is ON, evenwhen the output transistor 140 is turned on/off by a gate controlsignal, the OR circuit 131 can be maintained in the ON state.Accordingly, even when a PWM signal is used as the gate control signal,the state of the cell type power supply device 100 can be maintained inthe communication possible state. Namely, even when an N-channel MOSFETis used as the output transistor 140, the cell type power supply device100 can be operated in the same manner and produces the same effect asthe cell type power supply device 100 according to the secondembodiment, which uses a P-channel MOSFET as the output transistor 120.

Fourth Embodiment

In the cell type power supply device 100 according to the secondembodiment, the OR circuit 131 is arranged in the preceding stage of theEN terminal of the DC-DC converter 121, and the PWM signal output fromthe RF IC 122 is ORed with the detection signal output from thedetection transistor 130 at the OR circuit 131; therefore, even when aPWM signal is used as the gate control signal of the output transistor120, as long as the power switch 114 is ON, the cell type power supplydevice 100 can be maintained in the communication possible state. In thecell type power supply device 100 according to the fourth embodiment,the processing performed at the OR circuit 131 of the second embodimentis performed in the RF IC 122.

(Circuit Configuration)

FIG. 10 is a circuit example of the case where the inverter 123 of thecircuit of FIG. 5 of the first embodiment is replaced with a P-channelMOSFET. The gate terminal of the detection transistor 130 is connectedto the outer positive terminal 103, the source terminal thereof isconnected to the OUTPUT terminal of the DC-DC converter 121, and thedrain terminal thereof is connected to the INPUT terminal of the RF IC122. When the power switch 114 is OFF, the gate terminal of thedetection transistor 130 is connected to the INPUT terminal of the DC-DCconverter 121 via pull-up resister 134 to stabilize the gate terminal ofthe detection transistor 130 at the high level. When the detectiontransistor 130 is OFF, the INPUT terminal of the RF IC 122 is connectedto the GND via pull-down resister 137 to stabilize the INPUT terminal ofthe RF IC 122 at the low level. The OUTPUT terminal of the RF IC 122 isconnected to the gate terminal of the output transistor 120. An inverter133 is interposed between the OUTPUT terminal of the RF IC 122 and thegate terminal of the output transistor 120. The input terminal of theinverter 133 is connected to the OUTPUT terminal of the RF IC 122, andthe output terminal thereof is connected to the gate terminal of theoutput transistor 120. When the OUTPUT terminal of the RF IC 122 isopen, the input terminal of the inverter 133 is connected to the GND viapull-down resister 138 to stabilize the gate terminal of the outputtransistor 120 at the high level.

(Operation Description)

FIG. 11 is a timing chart showing changes of the input/output of eachterminal under PWM control by the RF IC 122 of FIG. 10. FIG. 12 is aflowchart showing a procedure of a process for switching on/off of thetransmitting/receiving operation by the RF IC 122 of FIG. 10. Thecontrol unit controls ON/OFF of the transmitting/receiving operation bythe wireless communication unit in accordance with the OR of the gatecontrol signal generated by the control signal generation unit andoutput from the OUTPUT terminal and the signal input to the INPUTterminal. Specifically, the control unit turns on thetransmitting/receiving operation when the OR of the gate control signaloutput from the OUTPUT terminal and the signal input to the INPUTterminal is the high level, and turns off the transmitting/receivingoperation when the OR is the low level.

As shown in FIG. 12, when the external load device 111 is in the initialstate (the power switch 114 is in the OFF state), the INPUT terminal ofthe RF IC 122 is at the low level, and the OUTPUT terminal thereof is atthe low level (step S21). Hence, the OR of the signal levels of thosetwo terminals is the low level; therefore, the transmitting/receivingoperation by the wireless communication unit is not ON. Accordingly, thecell type power supply device 100 is in the standby state in which thetransmitting/receiving operation is OFF. When the INPUT terminal isswitched from the low level to the high level, i.e., when the powerswitch 114 is turned on (step S22), the OR of the signal levels of thosetwo terminals is switched from the low level to the high level. Thetransmitting/receiving operation by the wireless communication unit isthereby turned on in accordance with control of the control unit, andthe state of the cell type power supply device 100 is switched from thestandby state to the communication possible state (step S23).

When the INPUT terminal is at the high level (Yes in step S24), thetransmitting/receiving operation by the wireless communication unit ismaintained in the ON state in accordance with control of the controlunit, whereby the cell type power supply device 100 is maintained in thecommunication possible state (step S26). When the INPUT terminal is atthe low level, the control unit switches between ON and OFF of thetransmitting/receiving operation in accordance with the signal level ofthe OUTPUT terminal. When the INPUT terminal is at the low level, andthe OUTPUT terminal is at the high level, the output transistor 120 isturned on by the high level of the gate control signal, and the motor115 is driving. Therefore, the cell type power supply device 100 shouldbe maintained in the communication possible state. Thus, when the INPUTterminal is at the low level (No in step S24), and the OUTPUT terminalis at the high level (Yes in step S25), the transmitting/receivingoperation by the wireless communication unit is maintained in the ONstate in accordance with control of the control unit, therebymaintaining the cell type power supply device 100 in the communicationpossible state (step S26). When the INPUT terminal is at the low level,and the OUTPUT terminal is at the low level (or open), the power switch114 is OFF, and the cell type power supply device 100 should be switchedfrom the communication possible state to the standby state for the sakeof reduction of unnecessary power consumption. Therefore, when the INPUTterminal is at the low level (No in step S24), and the OUTPUT terminalis at the low level (No in step S25), the transmitting/receivingoperation by the wireless communication unit is switched from ON to OFFin accordance with control of the control unit, thereby switching thestate of the cell type power supply device 100 from the communicationpossible state to the standby state (step S27).

As described in relation to FIG. 11, by the ON/OFF switching control ofthe transmitting/receiving operation by the control unit as describedabove, the transmitting/receiving operation can be turned off while thepower switch 114 is OFF, and can be turned on while the power switch 114is ON. Consequently, the cell type power supply device 100 according tothe fourth embodiment can use a PWM signal as the gate control signalwith fewer parts than the cell type power supply device 100 according tothe second embodiment without arranging the OR circuit 131 as done inthe second embodiment. Here, the communication function of the cell typepower supply device 100 is turned on/off in accordance with ON/OFF ofthe power switch 114. As described in relation to FIG. 5, however, thecommunication interval of the cell type power supply device 100 may bechanged in accordance with ON/OFF of the power switch 114. For example,shortening the communication interval when the power switch 114 is ONcan improve the response speed of the cell type power supply device 100to the instruction from the external information device 200, and canimprove connectivity of the communication with the external informationdevice 200. In addition, prolonging the interval between communicationswith the external information device 200 in the state where the powerswitch 114 is OFF can reduce unnecessary power consumption.

The method for controlling the ON/OFF switching of thetransmitting/receiving operation by the control unit is not limited tothe above. For example, the control unit may refrain from performing theON/OFF control of the transmitting/receiving operation by the wirelesscommunication unit while a gate control signal is output from the OUTPUTterminal. This enables the cell type power supply device 100 to maintainthe state immediately before the gate control signal is output from theOUTPUT terminal, i.e., the communication possible state, even when theoutput transistor 120 is turned on/off by the gate control signal, andthe voltage level of the input signal of the INPUT terminal changes.

Fifth Embodiment

When the motor 115 is used as the load of the external load device 111,the cell type power supply device 100 according to the fifth embodimentcan change the direction of the current that flows in the motor 115 ofthe external load device 111.

(Circuit Configuration)

FIG. 13 is an equivalent circuit diagram showing an example of the celltype power supply device 100 according to the fifth embodiment. The celltype power supply device 100 according to the fifth embodiment comprisesan H bridge circuit 160. The H bridge circuit is provided in parallelwith the cell. The H bridge circuit 160 includes four output transistors161, 162, 163, and 164. The first and third output transistors 161 and163 are P-channel MOSFETs. The second and fourth output transistors 162and 164 are N-channel MOSFETs.

The gate terminal of the detection transistor 130 is connected to theouter positive terminal 103. When the power switch 114 is OFF, the gateterminal of the detection transistor is connected to the inner positiveterminal 105 via pull-up resister 134 to stabilize the gate terminal ofthe detection transistor 130 at the high level.

The source terminal of the first output transistor 161 is connected tothe inner positive terminal 105, the drain terminal thereof is connectedto the outer positive terminal 103, and the gate terminal thereof isconnected to an OUTPUT 1 terminal of the RF IC 122 via an inverter 156.When the OUTPUT 1 terminal of the RF IC 122 is open, the gate terminalof the first output transistor 161 is connected to the inner positiveterminal 105 via pull-up resister 151 to stabilize the gate terminal ofthe first output transistor 161 at the high level. When the power switch114 is OFF, the drain terminal of the first output transistor 161 isconnected to the inner positive terminal 105 via pull-up resister 134 tostabilize the drain terminal of the first output transistor 161 at thehigh level.

The source terminal of the second output transistor 162 is connected tothe inner negative terminal 106, the drain terminal thereof is connectedto the outer positive terminal 103, and the gate terminal thereof isconnected to an OUTPUT 2 terminal of the RF IC 122. When the OUTPUT 2terminal of the RF IC 122 is open, the gate terminal of the secondoutput transistor 162 is connected to the inner negative terminal 106via pull-down resister 152 to stabilize the gate terminal of the secondoutput transistor 162 at the low level. When the power switch 114 isOFF, the drain terminal of the second output transistor 162 is connectedto the inner positive terminal 105 via pull-up resister 134 to stabilizethe drain terminal of the second output transistor 162 at the highlevel.

The source terminal of the third output transistor 163 is connected tothe inner positive terminal 105, the drain terminal thereof is connectedto the outer negative terminal 104, and the gate terminal thereof isconnected to the OUTPUT 2 terminal of the RF IC 122 via an inverter 157.When the OUTPUT 2 terminal of the RF IC 122 is open, the gate terminalof the third output transistor 163 is connected to the inner positiveterminal 105 via pull-up resister 153 to stabilize the gate terminal ofthe third output transistor 163 at the high level.

The source terminal of the fourth output transistor 164 is connected tothe inner negative terminal 106, the drain terminal thereof is connectedto the outer negative terminal 104, and the gate terminal thereof isconnected to the OUTPUT 1 terminal of the RF IC 122. When the OUTPUT 1terminal of the RF IC 122 is open, the gate terminal of the fourthoutput transistor 164 is connected to the inner positive terminal 105via pull-up resister 154 to stabilize the gate terminal of the fourthoutput transistor 164 at the high level.

OR circuit 145 is arranged in the preceding stage of the first inputterminal of OR circuit 131. The first input terminal of OR circuit 145is connected to the OUTPUT 1 terminal of the RF IC 122, and the secondinput terminal thereof is connected to the OUTPUT 2 terminal of the RFIC 122. Accordingly, as long as a gate control signal is output from oneof the OUTPUT 1 terminal and the OUTPUT 2 terminal, even though thereare two OUTPUT terminals, a high-level gate control signal is outputfrom the OUTPUT 1 terminal or the OUTPUT 2 terminal as in the secondembodiment, and regardless of whether the first and fourth outputtransistors 161 and 164 or the second and third output transistors 162and 163 are turned on, the state where the transmitting/receivingoperation of the cell type power supply device 100 is ON can bemaintained. Therefore, a PWM signal can be used as the gate controlsignal.

(Circuit Operation)

FIG. 14 is a diagram showing a terminal voltage of each transistor whichchanges in accordance with ON/OFF of the power switch 114 of FIG. 13.

When the power switch 114 is OFF, the first and third output transistors161 and 163 are OFF as their source terminals are at the high level, andtheir gate terminals are connected to the inner positive terminal 105via pull-up resisters 151 and 153 and thus are at the high level. Thesecond output transistor 162 is OFF as its source terminal is at the lowlevel, and its gate terminal is connected to the inner negative terminal106 via pull-down resister 152 and thus is at the low level. The fourthtransistor 164 is ON as its source terminal is at the low level, and itsgate terminal is connected to the inner positive terminal 105 viapull-up resister 154 and thus is at the high level. The detectiontransistor 130 is OFF as its source terminal is at the high level, andits gate terminal is connected to the inner positive terminal 105 viapull-up resister 134 and thus is at the high level.

When the power switch 114 is turned on, the gate terminal of thedetection transistor 130 is connected to the inner negative terminal 106via the fourth output transistor 164, and thus is switched from the highlevel to the low level, thereby turning on the detection transistor 130.As the detection transistor 130 is turned on, the second input terminalof OR circuit 131 reaches the high level, a drive voltage Vdd issupplied from the DC-DC converter 121 to the RF IC 122, the RF IC 122 isdriven, and the state of the cell type power supply device 100 isswitched from the OFF state to the communication possible state.

The cell type power supply device 100 according to the fifth embodimentreceives a code wireless signal relating to a switching instructionabout a motor rotation direction from the external information device200 via the wireless communication unit. When a code wireless signal forrotating the motor forward is received, the gate control signalgenerated by the control signal generation unit is output from theOUTPUT 1 terminal in accordance with control of the control unit. Incontrast, when a code wireless signal for rotating the motor backward isreceived, the gate control signal generated by the control signalgeneration unit is output from the OUTPUT 2 terminal in accordance withcontrol of the control unit. When a gate control signal is output fromthe OUTPUT 1 terminal, the first and fourth output transistors 161 and164 are turned on/off at the same time. Similarly, when a gate controlsignal is output from the OUTPUT 2 terminal, the second and third outputtransistors 162 and 163 are turned on/off at the same time. A gatecontrol signal is not output from the OUTPUT 1 terminal and the OUTPUT 2terminal at the same time. Accordingly, when the first and fourthtransistors 161 and 164 are on, the second and third output transistors163 are never turned on, and a malfunction of the circuit, and a shortcircuit etc. can be avoided.

As described above, by keeping one of the four output transistors 161,162, 163, and 164, here, the fourth output transistor 164, ON with thepower switch 114 turned off, the gate terminal of the detectiontransistor 130 can be switched from the high level to the low level whenthe power switch 114 is turned on. Namely, keeping one of the fouroutput transistors 161, 162, 163, and 164 ON enables detection of ON/OFFof the power switch 114 by the cell type power supply device 100. SinceON/OFF of the power switch 114 can be detected, even when the cell typepower supply device 100 comprises an H bridge control circuit forenabling forward/backward rotation of the motor 115, turning on/off ofthe communication function of the cell type power supply device 100, anda change of the communication interval etc. can be performed inaccordance with ON/OFF of the power switch 114.

The circuit included in the cell type power supply device 100 accordingto the first to fifth embodiments is a circuit with an external load, anexternal power supply and a power switch. Therefore, by attaching thecircuit of the cell type power supply device 100 in another electricequipment including an external load, an external power supply, and apower switch, the electric equipment can perform a similar operation andproduces a similar effect to the cell type power supply device 100according to the first to fifth embodiments.

While certain embodiments of the present invention have been described,these embodiments have been presented as examples, and are not intendedto limit the scope of the invention. Those embodiments may be embodiedin a variety of other forms; furthermore, various omissions,substitutions and changes may be made without departing from the spiritof the invention. Those embodiments and modifications fall within thescope and spirit of the invention, and fall within the scope of theclaims and their equivalents.

The invention claimed is:
 1. A cell type power supply device attachablealone or in series with an other cell in a cell box of an external loaddevice including a load, the cell box, and a power switch interposedbetween the load and the cell box, the cell type power supply devicecomprising: a housing having a shape and dimensions based on a cellstandard; a cell holder that holds an external cell in the housing, andincludes an inner positive terminal and an inner negative terminal thatare brought into contact with front and rear terminals of the heldexternal cell; an outer positive terminal provided on a front endsurface of the housing and connected to the inner positive terminal; anouter negative terminal provided on a rear end surface of the housingand connected to the inner negative terminal; an output transistorinterposed between the inner negative terminal and the outer negativeterminal or between the inner positive terminal and the outer positiveterminal; a control circuit that generates a control signal of theoutput transistor in accordance with an RF signal received from anexternal information device via an antenna; and a detection resisterinterposed between the inner negative terminal and the outer negativeterminal or between the inner positive terminal and the outer positiveterminal in parallel with the output transistor to change a voltage ofthe outer negative terminal or the outer positive terminal with respectto a reference voltage in accordance with ON/OFF of the power switch. 2.The cell type power supply device according to claim 1, wherein thecontrol circuit switches between ON and OFF of a transmitting/receivingoperation of an RF signal via the antenna in accordance with ON/OFF ofthe power switch which is determined based on a voltage level of theouter negative terminal or the outer positive terminal with respect tothe reference voltage.
 3. The cell type power supply device according toclaim 1, wherein the control circuit changes an interval betweencommunications with the external information device in accordance withON/OFF of the power switch which is determined based on a voltage levelof the outer negative terminal or the outer positive terminal withrespect to the reference voltage.
 4. The cell type power supply deviceaccording to claim 1, further comprising an internal power supplycircuit that generates a designated drive voltage from a cell voltage ofthe external cell, wherein the internal power supply circuit starts orstops supplying the drive voltage to the control circuit in accordancewith ON/OFF of the power switch which is determined based on a voltagelevel of the outer negative terminal or the outer positive terminal withrespect to the reference voltage.
 5. The cell type power supply deviceaccording to claim 1, further comprising: an internal power supplycircuit that generates a designated drive voltage from a cell voltage ofthe external cell; and a detection transistor that is interposed betweenthe control circuit and the inner positive terminal or between theinternal power supply circuit and the inner positive terminal and isturned on/off in accordance with a voltage level of the outer negativeterminal or the outer positive terminal with respect to a referencevoltage.
 6. The cell type power supply device according to claim 5,further comprising a logic circuit that receives inputs of the controlsignal and a detection signal indicating ON/OFF of the detectiontransistor and outputs to the internal power supply circuit or thecontrol circuit a logic operation result of the control signal and thedetection signal.
 7. The cell type power supply device according toclaim 6, wherein the control signal is a PWM signal.
 8. The cell typepower supply device according to claim 6, wherein a low-pass filter isarranged on an output side of the logic circuit.
 9. The cell type powersupply device according to claim 1, further comprising an H bridgecontrol circuit including four transistors to change a direction of acurrent to be supplied to the load, wherein when the power switch isOFF, one of the four transistors is ON.
 10. A cell type power supplydevice attachable alone or in series with an other cell in a cell box ofan external load device including a load, the cell box, and a powerswitch interposed between the load and the cell box, the cell type powersupply device comprising: a housing having a shape and dimensions basedon a cell standard; a cell holder that holds an external cell in thehousing, and includes an inner positive terminal and an inner negativeterminal that are brought into contact with front and rear terminals ofthe held external cell; an outer positive terminal provided on a frontend surface of the housing and connected to the inner positive terminal;an outer negative terminal provided on a rear end surface of the housingand connected to the inner negative terminal; an output transistorinterposed between the inner negative terminal and the outer negativeterminal or between the inner positive terminal and the outer positiveterminal; a control circuit that generates a control signal of theoutput transistor in accordance with an RF signal received from anexternal information device via an antenna; an internal power supplycircuit that generates a designated drive voltage from a cell voltage ofthe external cell; and a detection resister interposed between the outernegative terminal or the inner positive terminal and the internal powersupply circuit to change a voltage of the outer negative terminal or theouter positive terminal with respect to a reference voltage inaccordance with ON/OFF of the power switch.
 11. The cell type powersupply device according to claim 10, wherein the control circuitswitches between ON and OFF of a transmitting/receiving operation of anRF signal via the antenna in accordance with ON/OFF of the power switchwhich is determined based on a voltage level of the outer negativeterminal or the outer positive terminal with respect to the referencevoltage.
 12. The cell type power supply device according to claim 10,wherein the control circuit changes an interval between communicationswith the external information device in accordance with ON/OFF of thepower switch which is determined based on a voltage level of the outernegative terminal or the outer positive terminal with respect to thereference voltage.
 13. The cell type power supply device according toclaim 10, wherein the internal power supply circuit starts or stopssupplying the drive voltage to the control circuit in accordance withON/OFF of the power switch which is determined based on a voltage levelof the outer negative terminal or the outer positive terminal withrespect to the reference voltage.